8306922: IR verification fails because IR dump is chopped up

Backport-of: 9057b3503349ead7d995b1a705317324830eabb2

src/hotspot/share/opto/compile.cpp

@@ -551,28 +551,37 @@ void Compile::print_compile_messages() {
 
 #ifndef PRODUCT
 void Compile::print_ideal_ir(const char* phase_name) {
-  ttyLocker ttyl;
   // keep the following output all in one block
   // This output goes directly to the tty, not the compiler log.
   // To enable tools to match it up with the compilation activity,
   // be sure to tag this tty output with the compile ID.
-  if (xtty != nullptr) {
-    xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
-               compile_id(),
-               is_osr_compilation() ? " compile_kind='osr'" : "",
-               phase_name);
-  }
+
+  // Node dumping can cause a safepoint, which can break the tty lock.
+  // Buffer all node dumps, so that all safepoints happen before we lock.
+  ResourceMark rm;
+  stringStream ss;
+
   if (_output == nullptr) {
-    tty->print_cr("AFTER: %s", phase_name);
+    ss.print_cr("AFTER: %s", phase_name);
     // Print out all nodes in ascending order of index.
-    root()->dump_bfs(MaxNodeLimit, nullptr, "+S$");
+    root()->dump_bfs(MaxNodeLimit, nullptr, "+S$", &ss);
   } else {
     // Dump the node blockwise if we have a scheduling
-    _output->print_scheduling();
+    _output->print_scheduling(&ss);
   }
 
+  // Check that the lock is not broken by a safepoint.
+  NoSafepointVerifier nsv;
+  ttyLocker ttyl;
   if (xtty != nullptr) {
+    xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
+               compile_id(),
+               is_osr_compilation() ? " compile_kind='osr'" : "",
+               phase_name);
+    xtty->print("%s", ss.as_string()); // print to tty would use xml escape encoding
     xtty->tail("ideal");
+  } else {
+    tty->print("%s", ss.as_string());
   }
 }
 #endif
@@ -4991,8 +5000,8 @@ bool Compile::randomized_select(int count) {
 CloneMap&     Compile::clone_map()                 { return _clone_map; }
 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
 
-void NodeCloneInfo::dump() const {
-  tty->print(" {%d:%d} ", idx(), gen());
+void NodeCloneInfo::dump_on(outputStream* st) const {
+  st->print(" {%d:%d} ", idx(), gen());
 }
 
 void CloneMap::clone(Node* old, Node* nnn, int gen) {
@@ -5039,11 +5048,11 @@ int CloneMap::max_gen() const {
   return g;
 }
 
-void CloneMap::dump(node_idx_t key) const {
+void CloneMap::dump(node_idx_t key, outputStream* st) const {
   uint64_t val = value(key);
   if (val != 0) {
     NodeCloneInfo ni(val);
-    ni.dump();
+    ni.dump_on(st);
   }
 }
 

src/hotspot/share/opto/compile.hpp

@@ -135,7 +135,7 @@ class NodeCloneInfo {
   NodeCloneInfo(uint64_t idx_clone_orig) : _idx_clone_orig(idx_clone_orig) {}
   NodeCloneInfo(node_idx_t x, int g) : _idx_clone_orig(0) { set(x, g); }
 
-  void dump() const;
+  void dump_on(outputStream* st) const;
 };
 
 class CloneMap {
@@ -158,7 +158,7 @@ class CloneMap {
   int max_gen()                   const;
   void clone(Node* old, Node* nnn, int gen);
   void verify_insert_and_clone(Node* old, Node* nnn, int gen);
-  void dump(node_idx_t key)       const;
+  void dump(node_idx_t key, outputStream* st) const;
 
   int  clone_idx() const                         { return _clone_idx; }
   void set_clone_idx(int x)                      { _clone_idx = x; }